Manhole guard



Jan. l5, 1946. A w, w. sTEvENsoN 2,393,126 MANHOLE GUARD Filed March 24,1944 Sheet-Sheet l.

WITNEJJES Jan. 15,1946.

W. W. STEVENSON 'MANHOLE GUARD lFiled March 24, 1944 2 sheets-shea 2Patented Jan. *15, 1946 UNITED STATES OFFICE .MAN-HOLE GUARD Wilbur "W.Stevenson, dIittslmrgh, Pa.

Application March 24, 1944,. Senial.No. j 521,906

9 Claims.

Thefiirvention relatesfto vmanhole guards, by vwhiehis meantsstructuresthat are placed around amialom/fe street-manholes to .protect ,menworking in them. :against .injury y:by articles that may iallintoltheholes, and to v,protect :streettraic `suchia's pedestrians -fandvehicles `ragainst :injury byfreasonfof open manholes.

`:obliect Vof :the 1.1invention :is to provide sa sturdy .manhole iguardiformed of sections which .'mayifreadily .be assembled 'for use-.anddisassembledor transportation or for-storing in .za manholethroughoutfthe night, rwhich'swhenf-assembled .forms la .fri-gidstructure that :may vbe lfirmly lattached :to La -rnarrlzlole casing to'i afford itullprotection, nthe guard being :provided :with afgateWhch-is easilyoperable by workmenrenter- .ing sand deaiving aa,manhole.

V.A ,furthervobiectfis .to .provide ascreenadapted itobeaassociated"these-Itard .for 'closing the top of fthe ...manhole :to .protectworkmen ,against 'stoneslor other. missiles that might .enter the top:of'the Lgnardthezscreenbeing .readily closed fand lopenedfbyia workmanentering .and leaning the manhole.

',Elhe: preferred embodiment .of my invention risf y:vieuri-beingndioatedbythe A.lines :IV-IV 1- cna-Figs.

1 and 2 Eigfr .anc'elevation :of anv uprghtv-forrn ing a part of thesuperstructure of theiguard; -Iigf6rv azdet'ailedfvertical sectionalviewzof la post "formingipartfof 'za -Igate section, thegplane of Viewbeinglindicatedffby'the line vVI-V-I,..:Fig. l2; and "Figlfl a-planviewoff'lalscreen adapted tube-asso- 'ciated-"withfthe guardflbase which .isshown nin -dotted lines.

'The 'manhole Ig-uard comprises Jesser-itially 1a base 'I and asuperstructure each formed .of a plurality Vof separable 1parts'.adaptedto be telescopically assembled. nsitisshown Yin Fig. -1, the baseis-fformedof twolilike 5semi-circular sec- `tions, *each including La'semi-circular .lpipe 4 "adapted to-rest on the surface aofrra :street:surrounding -a vmanhole,and a '..semi-circular toe --board 5'whcseIlowenedgeis welded to the .outside of .pipe 4. One end of pipe 4 isprovided with a dowel' pin 6,'AFig. y'1,- Yad'aptedlto bemeceivedbyAthe" openend of"th'elike pipe roi the other yse'ction. fAiso,leach-,base sectionis provided v.with .fourssoeketsffl the form' oishort sections of pipe whose lower ends are welded ,to the top faceoi-pipe 4.. Each-ofv lthese sockets I is adapted to re- .ceive faneupr-ig-htlsection of the superstructure `ot the -lgguard which will.,presently be explained, the `sockets bei-ng `spaced :at equiangu-larrdis- -tar-iceszof 45 degrees for receiving eight Vuprigihts toro-rm fanoctagonal superstructure. l

.For-securely attaching the base of the guard toan annular .casing thatfor-ms the upper wall of a manholaeachk base section isprovided withmw-ardlyeXtending-lugsl-D vinthe forrn of plates AwhichTa-re' -weldedtothe top of circularbpesd, thel lugsbeing spacecl at .equaLinterVaIswhenthe sections of the base .areassernbled As shown .in Fig. 4azman-hole .casing Il is provided with .a sturdy beltflzbelow .each lugIliJ. lilngaging'A the shank of bolt i2 there is an upwardly extending'adapter llink-t3 whoselower end-is provided with .-a.keyholeslothav-ingits enlarged end upper- ,most tia-receive the head .of thebolt. 'The upper .end of i3 is,A provided with a horizontally extending;lange EIA 4having a vverticaloper'ring for receivingthe `smooth`.portion of. a.threadedb1`t t5 `which extends'upwardly through anopening Yformed. in. vl1-ig Il). The .upwardly vprojecting" end of bolt-l5..is-.provided withahand nut `I6 whose lower V-iiace Vengages .the.topoflug Il), irnily to .anchor thebase when all the-nuts l are thus-tig-htened,l

When the ysectionso-f basel are thusattached :to afmanhole casing,jtoeboard I5 preventsstones or other missilesI rolling on the street from.entering 'the manhole. To .prevent street surface wate-rviromf-flowinginto the manhole, the bottoms of tubes. Lmay be sealed .to the tops ofcasing -li byfasuitablephstic Acompound as indicated at r`if! Fig. 4,,and :the .meeting vertical edges of toeaboards f5 may be .sealedlbyadhesive tape.

.The :superstructure .comprises eight uprights, 'six-of whichareoi .thesaine orm as the upright l2i! .shown in Eig. ,5, 4.and two .of whichthatjform gates fareesimilar :to upright-,T20 but 4diier details thatwillpresentlybefexfilained Each uplright `210 .comprisesa verticalpost'2l in the vform `ofna, pipe; andan .upwardly inclined beam :22 intheforxn of a pipe whose inner `end is welded to .the-topof post Hand towhose outer endthere is f'welded :a ,downwardly extending pin 2d whichmay be a.shortLsection..oieJ pipe. Betweenbeam .22 fandipost v2| there`is` a 4sheet metal i'lag 25 .whose Aends areweldedto .theY beam andpost. The exposed {facev of this fflag '.maybe paintedredlto,indicate.dang.er, `andlitlniayv be .provided with a cube cornerreflector 26 to warn approaching automobilists of the presence of themanhole guard.

One of the gate sections, namely, that shown at 30 in Figs. l and 2, isthe same as upright 20 with the exception that the outer end of beam 22of gate section 30 is provided at its lower side with a short pipe 3|which is welded to the beam. Within the confines of pipe 3i the lowerface of beam 22 is Vperforated to receive a vlocking bolt of the othergate `Vsection presently' tobe ex`- plained.

In assembling superstructure 2 upon base I, the lower end of post 2l ofgate section 30 is inserted in one of the tubular sockets I of the base.Thereafter, proceeding in a 'clockwise direction as shown in Fig. 1, thesix like uprights n 20 are similarly placed successively on the base,

each post of an upright being received by av socket l, and thedownwardly extending pin 24 at the outer end of'beam 22 of each uprightbeing telescopically received by the upper end of the tubular postpreviously positioned.

'Ihe last upright of the structure to be assembled is gate section 35,whose construction will now be explained. As shown in Fig. 2, gatesection 35 is formed of a tubular post 36 whose lower end terminatesabove the top of the toe board of the base so that the gate section mayswing outwardly. Beam 3l' of the gate section 35 is provided at itsouter end with a long tubular pin 3B which is received by post 2i of thelast of uprights 23 to be positioned upon base l. The upper end of ypin38 is provided with a laterally extending collar 39 which bears upon thetop of post 2l in which the pin is inserted, the construction being suchthat pin 38 lying in post 2l acts as the pintle of a hinge pivotally tosupport gate section 35.

As shown in Fig. 6, post 36 of gate section 35 is provided with avertically movable locking bolt 40 which may be tubular in form andwhich is positioned within and guided by a tube 42 arrangedconcentrically within post 36 and suitably welded to it at itsupper end.The lower end of locking bolt 40 is provided with a latch 43 whichextends through an inverted J-shaped slot 44 formed in the portion ofthe wall of post 36 that faces the interior of the guard so that latch'43 may be operated by a workman within the guard and is not readilydiscernible by anyone outside Aof the guard. When the gate is unlocked,latch l43 lies at the lower end of the longer stem of slot 44; Y

When the two sections of base l vhave been assembled as shown in Figs. 1and 2 and attached to a casing il of a manhole as shown in Fig. 4,workmen may enter the manhole guard through gate sections 30 and 35which are then open to their dotted line positions shown in Fig. 1. Aworkman then swings the gate sections `to their closed position shown infull lines in Fig, 1 and brings bolt 4B of gate section 35 into registrywith tube 3l on beam 220i gate section 30. The workman then lifts latch43 to cause its upper end to engage the opening in the bottom of beam22of gate section 30 and turns latch 43 so that it Vlies in the shorterportion of slot 44, in which position the' Vgates are locked. Themanhole guard then forms a sturdy rigid structure which protects bothworkmen and pedestrians.

To disassemble the guard itis only necessary to lift the gate sections30 and 35 and the uprights 20 fromv the sockets 1 of the base, to loosenhand nuts I6 to release adapter links I3 from l 3. A manhole guardcomDriSrl their engagement with stud bolts l2, and to separate basesections by moving them laterally from each other. The thus separatedparts of the superstructure and base are light and easily handled.Furthermore they are of such relatively small size that at the end of awork day they may be stored in a manhole over night,

An advantage of the guard is that when it is assembled and connected toa manhole casing it forms a .sturdy structure that is capable ofwithstanding heavy external impactswithout being moved or distorted.Also, the gate sections 3D and 35 have the same external appearance asthe uprights 20, and hence are not readily discernible by curious ormalicious pedestrians who might tamper with or open the gates.

To protect workmen in a manhole against stones or missiles that may fallor be thrown into the top of a manhole guard, the top of the hole may beprotected by a screen of the form shown in Fig. 7. This screen comprisesa plate 50 which is provided with a pair of openings 5i adapted'toreceive adjacent sockets 1 of base l. To plate 50 there is pivotallyconnected a-three-part screen having a central section 52 and a pair ofouter or Wing sections 53. The central section is formed of a U-shapedrod 54 whose ends are provided with eyes that engage holesin plate 50,and a protecting screen attached to the rod Each wing section 53 is alsoformed of a U-shapedrod 55 whose ends are provided with eyesforpivotally mounting it on rod 54, the space within each rod 55 beingprovided with aprotecting screen.

When the screen is assembled with the manhole guard its wings 53 arefolded upon central section 52 and the latter is swung upwardly to aside of the guard. The last workman to enter a manhole pulls the screendown after him, and, reaching over the sides of the screen, swings wings53 to their horizontal position. The central por-V tion of the screen isheld in its horizontal position by its engagement with the tops of 4handnuts i6, and wings 53 may be held in their horizontal i positions bylugs 56 attached to and extending inwardly from tubes 4 of base I. 'Whenworkmen leave a manhole, the screen may readily be opened by rst foldingwings 53 upon central section 52, and then swinging the latter upwardly.

According to the provisions of the patent statutes, I have explained theprinciple and operation of my invention, and have illustrated anddescribed what I now consider to be the best embodiment ot. it. However,I desire to have it understood that, within the sco-pe of the appendedclaims, the invention may be practiced otherwise than specificallyillustrated and described.

I claim:

l. A manhole guard comprising a continuous base formed of a plurality ofseparable parts, directly connected to each other, and a plurality ofseparable uprights removably supported by the base and removablyconnected directly to each other to form an enclosure, lat least one ofsaid uprights being pivotally mounted to' form a gate.

2. A manhole guard'comprising a base formed of a pairV of like separableparts telescopica-ily assemblable with each other to form a continuoussupport, and a superstructure comprising a plurality of separableuprights removably supported by the base and removably connecteddirectly to each other to form an enclosure,at least one of said uprghtsbeing pivotally mounted to forma gate i Y gY a base formed ofr .a pairof telescopically assemblable'sectioris each comprising a pipe ofsemi-circular, shape and a semi-circular toe board attached to the pipe,and a plurality of separable uprights removably supported by the baseand removably con nected to each other to form an enclosure, at leastone of said uprights being pivotally mounted to form a gate.

4. A manhole guard comprising a continuous base formed of a plurality ofseparable parts directly connected to each other and provided withvertically disposed sockets, and a plurality of uprights each includinga post adapted to be telescopically received by one of said sockets,each of said uprights being detachably connected directly to an adjacentupright, and at least one of said uprights being pivotally mounted toform a gate.

5. A manhole guard comprising a base formed of a plurality of separableparts provided with vertically disposed sockets, and a plurality ofuprights each including a post whose lower end is telescopicallypositioned in one of said sockets, each upright including an upwardlyinclined beam having a pin at its outer end telescopically positioned inthe post of an adjacent upright, and a gate section pivotally supportedby one of said uprights.

6. A manhole guard comprising a base formed of a plurality of separableparts provided with vertically disposed sockets, a plurality o1'uprights each formed of a tubular post 'whose lower end istelescopically positioned in one of said sockets and of an upwardlyinclined tubular beam having a pin in its outer end telescopically posidtioned in the post o! an adjacent upright, and a gate section pivotallysupported by one of said uprights. i

7. A manhole guard comprising a base formed of a plurality of separableparts provided with vertically disposed sockets, a plurality of uprightseach formed of a tubular post whose lower end is telescopicallypositioned in one of said sockets and of an upwardly inclined tubularbeam having a pin in its outer end telescopically positioned in the postof an adjacent upright, and a gate section formed of a tubular post andan upwardly inclined beam having at its outer end a downwardly extendingpin telescopically received by the tubular post of an adjacent uprightfor pivotally supporting the gate section.

8. A manhole guard comprising a base, a superstructure connected to thebase, and a screen within the base :for covering a manhole, said screencomprising a plate detachably connected to said base, a centrallydisposed screen section pivotally attached to said plate, and wingscreen sections pivotally attached to the sides of said central section.

9. A manhole guard comprising a base, a superstructure formed of aplurality of uprights detachably connected to the base; and a screenwithin the base formed of a plate detachably connected to said base, acentral screen section pivotally attached to said plate, and wing screensec tions respectively pivotally attached to the sides of said centralsection.

WILBUR W. STEVENSON.

